S.I.D-Sound (시드 사운드), short for Studio. Innocent Dreamers-Sound project group, was a South Korean indie music production group formed on July 24, 2005. Active until May 4, 2018, the group was renowned for its work in pop, original albums, animation, and game music, along with its regular live performances. The group consisted of Lee Jongseong, also known as tacat, the founder responsible for composition, arrangement, mixing, and mastering; Kang Minhoon, or BLOODMOON, a co-founder with expertise in classical composition; Lee Sangyong, or HiTaZ, a composer who later launched the electronic project Cradle Edge; Kim Minseok, or 4-parts, a prodigious composer known for the track "Yeolae-a"; Ye Eunsu, or ampstyle, a composer who later performed as Dalui Haru before passing away in 2020; Cho Sehee, or PARABIRTH, who contributed as a composer and arranger; Kwon Suhyeon, or Aragon, the lead composer skilled in orchestral arrangements; Moon Changhwan, or lizt, the group’s bassist; and Kim Kihyun, or Cosmic Sound, who joined in 2014 as a producer and composer. S.I.D-Sound released seven studio albums, beginning with Innocent Eyes (2007) and ending with 난정서 (2018). Among their notable works are DECIBE1 M♠GIC! (2008), Fate Symphonia (2013), and WILL (2013), an acoustic album featuring re-arranged and original tracks. The album WILL (Acoustic), released on April 10, 2013, entered Bugs' Top 100 Folk/Acoustic albums chart at rank 50 on the week of January 26, 2026.